Determination of the stress state in the Andean Cordillera Frontal near the border between Argentina and Chile
View/ Open
Date
2015Author
Martino, Roberto D.
Giambastiani, Mauricio
Rocca, Ricardo J.
Guereschi, Alina B.
Huerta Soaje, Pedro J.
Marcet, Juan E.
Metadata
Show full item recordAbstract
The initial state of stress is an important parameter in underground
excavations. From its knowledge, it is possible to calculate the stresses induced
around the excavation and the necessary support for stabilization. This task
becomes critical when the excavations have great dimensions such as caverns and
when rock overburden is significant. Different methodologies are discussed,
including simple regional stress maps, the survey of surface paleostress and
hydraulic fracturing executed in borehole between 500 and 800 m deph. These
methodologies have been applied in the Andean Cordillera Frontal, where the
Agua Negra tunnel will be built between Argentina and Chile. This area is affected
by the subduction of the Nazca plate beneath the South American plate. This
setting generates that the greatest principal stress σ1 has a W-E orientation and
relationship with the vertical stress (σ2) reaches about 1.4.